Freedom to live your life as you see fit does not seem like a controversial political stance at first, or even a political stance at all, until it is applied to civil rights, economic freedoms, and social justice. Application of this basic tenet of libertarianism is what Brennan (A Brief History of Liberty) aims to do here, beginning with an explanation of the political philosophy itself— an umbrella term for several ideologies constructed from the premise that each individual is a sovereign entity—then systematically describes what would reasonably follow when the ideas are consistently applied to politics or life. In Brennan’s formulation libertarianism is a legitimate political alternative to the prevailing American two-party system: surprising to left, right and center alike. Libertarianism isn’t a radical philosophy with outlying political proposals; at times its stances align with liberals, on expansion of human rights and civil liberties, and at times with conservatives, on promoting small businesses. Brennan structures his book as a series of plausible queries and hypothetical scenarios, but his attempts to counter criticisms read more as evasions or appeals to abstractions. Instead of being able to pick this up and read clean, concise answers, readers will be left with more unanswerable questions. (Nov.)